Dead key eliminator electrical musical instrument



J. M. HANERT Jan. 11, 1966 DEAD KEY ELIMINATOR ELECTRICAL MUSICAL INSTRUMENT Filed Aug. 9, 1960 United States Patent iOdi-ice Patented Jan. ll, 1966 3,229,022 DEAD KEY ELIMINATGR ELECTRICAL ,-MUSICAL INSTRUMENT AvJohn M. Hanert, .Des Plaines, Ill., assigner to Hammond Organ Company, Chicago, Ill., a corporation of `Delaware Filed Aug.`9, 1960, Ser. No. 48,383 "1 Claim. (Cl. 84-L17) The present invention relates to electrical musical instruments of the organ type, and more particularly to a two manual organ having the advantages of unification -without theusual disadvantages associated therewith. As will be apparent, the invention also applies to unified organs where the unitication bears an octave or other xed relationship.

Broadly, it is an object of the present invention to provide a novel arrangement such that a single group of oscillators can be used in a unified organization in which an oscillator is made to sound from more than one key -without the usual unication disadvantage of causing what is commonly referred to as dead keys.

-More specifically, an additional object is to provide a novel two manual electronic organ with pedal bass, which provides the following characteristics and advantages. The upper keyboard, played normally by the right hand, provides polyphonic bass and treble accompaniment sections, and a highly variable solo section which is of the automatic high-note select type. If desired, the accompaniment and solo sections may be unified. There is a .polyphonic bass and treble accompaniment section playable upon a lower keyboard, and both polyphonic sections require a minimum number of oscillators consistent with 4the number of notes playable thereby. The organ has the further characteristic that when both `key-boards are connected to-the same oscillators, playing of keys upon one of -the keyboards does not result in dead keys in the same .location upon the other keyboard. Additionally, irnproved means-are provided for balancing the bass and treble-accompaniment sections, and a novel arrangement is used for coupling the accompaniment and solo sections vupon the actuation of a singlecontrol tab such that the solo section is automatically attenuated a desirable amount when it is coupled with the accompaniment sections.

Inthe specific arrangement shown, it may be considered that an objective is to provide anovel two manual organ having a high degree of responsiveness and musical merit -which may .be manufactured at minimum cost and with minimum complexity without the usual compromises associated with instruments manufactured at approximately the same cost.

Other objects and advantages will become apparent from the followingdescription of alpreferred embodiment .ofmy invention which is illustrated in the accompanying drawings.

The single figure of the drawings is an electrical circuit .diagram of an organ embodying the features of my invention, much ofthis-circuit being illustrated in block form where well known circuits are available for the various blocks.

In general, there are a plurality of oscillators indicated generally bythe numeral 10, only two of which are illustrated in detail, since the additional oscillators may be of the same type as those illustrated. These oscillators comprise the polyphonic or accompaniment sections, and are playable upon either the upper or the lower keyboard and preferably are divided into two grouups at the break indicated at 12, so as to provide separately playable treble and bass sections. By so doing, the character of the tone from the bass section may be different from that of the treble section, if desired.

As will be explained in greater detail presently, the specifically illustrated polyphonic or accompaniment oscillators are arranged to sound with flutes tones, strings tones, or reed tones, or any mixture thereof, and, as previously mentioned` the bass section may sound differently from the treble section. The tone characteristics set out above are merely representative of a suitable arrangement, and should not be considered as limitative, since it is a simple expedient in the art to supply tones of a character other than these.

As the Lipper keyboard is played with the right hand, the highest note played at any one time sounds upon the solo sec-tion, the tones for which are generated in a solo generator 14. T-he signal from this generator is passed through formant circuits, followed in turn by envelope control circuits and an arrangement for setting the relative volume level of the solo section, these circuits being indicated by the box 16.

A pedal bass section is provided at i8, and tbc output from the pedal bass section, the solo section, the treble accompaniment sections of bolli keyboards, and the bass accompaniment sections of both keyboards are mixed, controlled, and amplified in the mixer, control, and output section at Ztl, the signal it the power level being passed to an acoustic translating device such as the speaker at 22.

In addition to the above, the bass accompaniment section and the treble accompaniment section, as will be explained, have their relative volume levels selected by the actuation of an Accompaniment Balancer indicated gcnerally at 24. Coupling, as between the accompaniment sections and the solo section, is accomplished 'oy a single Accompaniment to Solo Coupler control and associated circuit indicated generally at 26, thereby obviating the necessity of coupling the notes between the solo and accompaniment sections individually as is the common practice. Additional control arrangements and circuit features will be discussed in connection with the, more detailed description of the invention which follows.

My Patent No. 2,645,968, issued luly 2l, 1953 for Electrical Musical Instrument, describes :ind illustrates an arrangement by means of which a polyphonic oscillator section may be constructed with a greatly reduced number of tubes by so arranging the circuit that one oscillator can serve for providing :i pair of adjacent semitones or, toward the bass end of the scale, three adjacent semitones. The instrument of the present invention uses this type circuit, and in the interest of detinitcncss, two such oscillator stages are shown, the one at 28 providing a pair of adjacent semitones, whereas the one toward the leftthat is, toward the bass end of the scale-indicated at 30, provides three adjacent semitones. The broken lines at 32 indicate that additional oscillators similar to that at 3l), may be provided toward the bass end of the scale, while the break at 34 indicates that oscillators, similar to that at 28, may be used toward the right or treble end of the scale.

Cei/tain of the leads are broken at 12, this being the point at which the bass accompaniment section ends and the treble accompaniment section begins. -To the right of this point, oscillators similar to those at 23, excepting for the values of certain of the circuit constants, as will be understood, are used for providing the tones of the treble accompaniment section.

The upper keyboard is provided with four bus bars indicated at 36, 3S, 40, and 42. These bus bars run the length of the upper manual excepting that the upper bus bar 36 is interrupted at the point i2, and, for convenience, the right hand extension or equivalent thereof is indicated by the numeral 36a. The lower keyboard is provided with two bus bars 44 and 46 which similarly extend the length of the keyboard excepting that the upper bus bar 44 is broken at 12, with the right hand .portion being indicated by the numeral 44a. The upper Ithe bass end of the upper manual, is provided with contacts 48, 50, 52, and 54 associated in normally open position with the bus bars 36, 38, 40, and 42 respectively.

The same key in the lower manual has two contact-s 56 and 58 similarly associated with bus bars 44 and 46 respectively. The adjacent Cit keys in the upper and lower manuals have similar contacts indicated in the same order by the numerals 60, 62, 64, 66, 68, and 70. The keys in the upper and lower manuals for the next semitone at D have a similar arrangement excepting that there are no contacts associated with the bus bars 36 and 44, the remaining contacts, in order, being indicated by the numerals 72, 74, 76, and 78.

These contacts are wired in the following relationship. Contacts 58, 70, and 78, associated with the lower bus bar 46, are connected together and through a load resistor to a lead 82 connected to the anode of a triode 84. The lead 82 is also connected to ground through a capacitor 86. Of the contacts associated with the second bus bar 44, contact 68 is connected to upper bus bar contact 60, and contact 56 is connected to upper bus bar contact 48. Skipping the solo section contacts associated with bus bars 42 and 40 for the moment, the contacts 50, 62, and 72 associated with bus bar 38 are connected together and, through a load resistor 88 having the same value as resistor 80, to the lead 82. In addition to the connection previously mentioned, contact 60 associated with bus bar 36 is connected through a capacitor 90, resistor 92 and capicitor 96 in series to a lead 94 connected, in turn, to the cathode of triode 84. Similar contact 48 is connected between capacitor 96 and resistor 92.

The grid of the triode 84 is connected through a capacitor 100 to one end of a tuning inductance coil 102, the other end of which is conected to a signal lead 104. A tuning capacitor 106 is connected in parallel with the coil 102, and a tap 108 near the lower end of the inductance 102 is connected to the cathode lead 94. A resistor 110 connects a signal lead 112 to the junction between the capacitor 100 and the inductance 102. The grid of triode 84 is also connected by a resistor 98 to a lead 114 connected to turn to a vibrato line 116 which operates in a manner to be described presently.

Signal lead 112 is connected to ground through a capacitor 118 and through a switch 120, which may, for instance, be labeled Bass Accompaniment-Flutes, to a lead 122 connected in turn through an attenuating re sistor 124 to a bass accompaniment signal line 126.

Signal lead 104 is connected to ground through a resistor 128 and through a resistor 130 and switch 132, to the lead 123. The switch 132 may be controlled by a tab labeled, for instance, Bass Accompaniment-Strings.

In order to provide still greater tonal variations, the junction between switch 132 and resistor 130 is connected through a mesh comprised of a resistor 134 and capacitor 136 in parallel to a switch 138 connected in turn to the signal line 126. The switch 138 is controlled by a tab which may appropriately be labeled Bass Accompaniment-Reeds. To prevent attenuation of the bass accompaniment reeds signal when either switch or switch 132 is closed, a decoupling resistor 124 is used in the common lead from switches 120 and 132.

Bus bar 36 is connected to the signal lead 104 and through a switch 140 to the bus bar 44. Bus bar 38 is connected through a switch 142 to bus bar 46 which in CII turn is connected to a B+ voltage source represented by the terminal 144. i

The portion of the circuit just described operates in the following manner. lf the D key of the lower manual is depressed, this will close contact 78 against the bus bar 46. The B+ voltage is thus applied by way o'f the bus bar 46, contact 78, and resistor 80 to the anode of triode 30. The circuit, therefore, goes into oscillation with the tuing thereof being determined largely by the values of the inductance 102 and capacitance 106. As explained in the previously referred to patent, this resuts in the sig nal appearing in the line 112 in a form which approximates a sine wave, and this signal therefore has typical flutes characteristics. The signal simultaneously appears in the line 104, but here it has a rich harmonic structure which gives the signal a strings quality. By removing some of the lower frequencies from this signal by means of the mesh 134-136, the character becomes more that of a. reeds type tone. Thus, by closing any one or more of he switches 120, 132, or 138, any one, two, or all three of these signals may be placed upon the line 126.

lf the C# key is depressed instead of the D key, contact 70, rather than contact 78, will be closed against the bus bar 46, but since these contacts are in parallel, the effect upon the oscillator is the same. However, the closure of contact 68 against bus bar 44 places capacitor 9), resistor 92, and capacitor 96 in series across the small tapped portion of the inductance 102, with the result that the tuning of the oscillator is shifted one semi-tone toward the lower frequency end of the scale, thus giving the C# tone rather than D tone. If the C key is played, Contact 58 acts the same as contact 70 or 78, but contact 56 connects capacitor 96 via bus bar 44 across the small tapped portion of inductance 102. This shifts the signal an additional semitone downwardly, and gives the note C.

If the D key of the upper manual is played, contact 72 will be closed against bus bar 38, with the result that the action is exactly the same as previously described, excepting that the B+ voltage is supplied to the anode by way of the resistor 88 rather than by way of resistor 80. This same action is true with the C# key and the C key, and since contact 60 is in parallel with contact 68, and 4S is in parallel with 56, the same performance is obtained regardless of whether the keys are played upon the upper or the lower manual so far as the accompaniment section is concerned. rThis statement assumes of course that the B-lswitch 142 is closed, and that the values of the resistors 80 and 88 are the same, which is the preferred arrangement.

On the other hand, if, for instance, the D key of the lower manual and the D key 0f the upper manual are simultaneously played, the D note will sound, but B+ current under these conditions is supplied to the anode by way of resistors 80 and 88 in parallel. This raises the potential of the plate considerably and results in the oscillator oscillating with a much greater amplitude so that the D note sounds much louder.

Thus if the musician is playing upon both manuals simultaneously and plays the same note upon both manuals, this note will stand out by being louder. There are, therefore, no dead keys produced in one manual by playing upon the other manual, thus overcoming a very serious disadvantage ordinarily present when a single group of oscillators is relied upon to supply the notes for fore than one manual.

What has been said with respect to the D key, of course i applies to the Cit and C keys, since the anode resistors 80 and 88 alternatively or together in parallel are common to all of the notes playable from a single oscillator stage.

The oscillator stage at 28 is substantially identical to the one at 30, excepting that it supplies the tone signals for two adjacent semitones instead of three. In this specie instance these notes are Dit and E immediately above the notes supplied by the stage 30. As with the previously described stage', B+ is supplied to the anode by way of resistor 146 whenever one of the two keys which energize and tune the oscillator are played upon the lower keyboard, whereas the anode current passes by way of resistor 148 when the similar keys are played upon the upper manual. As with the previous example, when both keys are played, the potential upon the anode is higher, since current is supplied to the plate through resistors 146 and 148 in parallel.

Beyond the break 12v toward the higher pitched end of the keyboard' the oscillators are not' shown but are substantially identical to the" ones indicated at 28, excepting for the values of the circuit constants, so that, in each instance, oscillationis at the appropriate frequency. For convenience, all of the leads and circuit elements at the right hand end ofthe drawing which are substantial duplicates of those at the left hand end have been given the same numbers with the subscript a..

The Accompaniment Balancer 24' comprises a potentiometer having a resistor element 150 connected at one end to the bass' accompaniment lead 126 and at the opposite end to the treble accompaniment lead 126a. The slider 152 is connected by a lead 154 to a mixer, control and output system at 156, capacitors 158 and 160 in series being connected across the resistor element 150 with the center point being connected'to the lead 154. Thus by movement of the slider 152 the'relative balance in the output of the bass accompaniment and treble accompaniment sections` can be adjusted as desired without appreci` ably disturbing the overallvolume level of the accompaniment.

By operation of a suitable control, the potential in the vibrato line 116 connected to the oscillator grids can be made to vary in a cyclical fashion at a rate of about 7 cycles per second by a vibrato oscillator at 162 as is explained in the previously mentioned patent; see also Patent No. 2,580,424, issued January l, 1952. Inasmuch as this cyclical variation in the potential at the oscillator grids remains uniform for any particular setting of the vibrato control, the amount of vibrato produced-in other words, the amount of the frequency shift of the oscillator signal-is a function of the magnitude of this variation in grid voltage as compared with the magnitude of the potential at the oscillator anode. Since playing the same key upon both upper and lower manuals has the effect of increasing the anode potential, the amount of vibrato grid potential variation is less in proportion, and therefore the amount of vibrato produced when the keys in the two manuals which play the same note are played together will be slightly less than it is when only one key is played. The overall effect therefore of playing two keys for the same note is to provide the tone for this note in the output at a considerably higher volume level than normal, but with slightly less vibrato. This is an advantageous feature, since when a tone in a passage is loud by comparison with other tones, it should preferably remain closer to its true pitch. Otherwise, the vibrato tends to become excessively apparent in the music.

In the upper manual, the solo section bus bars 40 and 42 are grounded, and each of the upper manual keys has a contact associated with each of these bus bars. Each of these contacts associated with the bus bars 40-for instance, contacts 52, 64, and 74 of notes C, Cit and D respectively-are connected together and to a lead 164 connected in turn to the envelope control 16 of the type explained in previously mentioned Patent No. 2,645,968. The arrangement is such that whenever the line 164 is grounded, the solo signal from the generator 14 will appear upon the signal line 180.

This oscillator is tuned by a capacitor 168 and a parallel connection of a plurality of inductances 170 in series. The junctions between the individual inductances are connected to the individual contacts associated with the bus bar 42 so that, for instance, if the D key is played so as to bring contact 76 against bus bar 42, all of the inductances between contact 76 and the solo generator will be placed in series across the capacitor 168. Similarly if the Ct key is played so as to bring contact 66 against the bus bar 42, the same circuit will be established excepting that one additional inductance will be placed in the series connection.

The individual inductances are so tuned that whenever any key is played on the upper manual, the appropriate tone will be sounded. Furthermore, if several keys areplayed simultaneously, only the highest of the played keys will aifect the tuning, since additional grounded connections below this point do not change the number of individual inductances inthe series circuit. Whenever any group of keys is played upon the upper keyboard,therefore, all of the tones associated with the individual keys can be sounded simultaneously upon one or the other of the accompaniment sections while simultaneously the highest key played will produce an appropriate tone signal from the solo generator 166.

The output from the solo generator is passed to a control section 16 which includes formant circuits for giving the type of tone selected. This section also includes envelope control circuits for producing percussive or sustained effects as desired, and includes a volume or balancing control for adjusting theloudness of the output from the solo section.

From the control circuit 16 the solo signal passes to line 180 connected through attenuating resistors 182 and 184 in series to the lead 154 which carries the mixedA signals from the -bass and treble accompaniment sections. One of these resistors-for instance, 182-is bridged by a switch 186 which is ganged with the switches 142, 140, and g so that as the switches 142, 140, and 1f40a are closed, switch 186 is opened. When the instrument is played with the Accompaniment to Solo Coupler switch 186 in the closed position, and switches 142, 140, and 14011 in the open position, it will be apparent that the lower manual will play in the bass and treble accompaniment sections, whereas the upper manual will play the solo section only, the B+ bus bar 38 for the upper manual accompaniment section being disconnected at the switch 142, and the tuning connections being disconnected at the switches 140 and 140a.

Under these conditions, the resistor 182 is shorted, and therefore the volume level of the signal from the solo generator will be relatively high so as to be in balance with the output of the accompaniment sections played upon the iower manual. By shifting the Accompaniment to Solo Coupler control so as to open switch 186 and close switches 142, 148, and 14811, the accompaniment sections playable by the upper manual will be energized and will be coupled with the solo section so that these two sections play simultaneously upon the upper manual while the accompaniment sections are additionally playable upon the lower manual. Since under these conditions the switch 186 is open, the resistor 182 is inserted in series with the resistor 184 in the solo output, and therefore the volume level of the solo section will drop, so as to maintain a balance between the solo section together with the coupled accompaniment sections playable upon the upper keyboard, and the accompaniment sections playable from the lower manual.

Solo vibrato is produced by a lead 172 which connects the solo generator 166 to the vibrato oscillator 162. As explained in the previously mentioned patents, the connections preferably should be such that the vibrato voltage in the lead 172 is out of phase with the vibrato voltage in lead 116 so that the vibrato effect produced in the solo section is out of phase with that produced in the accompaniment sections.

The pedal bass section 18 previously mentioned is connected by a lead 174 to the mixer, control, and output section 156. In this section the pedal bass signal, the bass accompaniment signal, the treble accompaniment 7 signal, and the solo signal are mixed, tone controlled, amplitied, and the overall volume is regulated by a swell control, after which the signal is passed to the power amplifier and thence to the speaker 22.

From the above description of a preferred embodiment of the invention, it will be apparent that an instrument of the full organ type is provided in which one manual can play accompaniment sections, whereas a second manual can play a solo section and also can be unied so as to play the accompaniment sections along with the solo section, and that, in addition, there are no dead keys produced in one of the manuals which plays the accompaniment sections whenever a similar key upon the other manual is simultaneously played. Furthermore, the arrangement is such that whenever similar keys in the two manuals are played'under conditions where the solo and accompaniment sections are unied, the particular note so played will stand out at a higher volume level, but that the vibrato upon the tone will not be increased, and, in fact, will be decreased somewhat. Also, the instrument has an Accompaniment to Solo Coupler control which automatically attenuates the output from the solo section a desired amount whenever the accompaniment sections are coupled to the solo section. Additionally, a single Accompaniment Balancer control adjusts the relative loudness of the bass and treble accompaniment sections without disturbing the overall balance.

The above specitically described embodiment is directed for purpose of illustration to unification of the type in which an oscillator may be called upon to sound when one or another or both keys are played, and in which the two keys in question are in separate manuals. It should be understood, however, that the invention is broader than this specific application. That is, it relates to all types of unification, which have the common feature that a single oscillator is called upon to sound when any of different keys are played, and in which it is Vdesired to have the sound at a higher volume level when more than one of the keys controlling the same oscillator are played together so as to eliminate dead keys. Whether these keys are in separate manuals or are, for instance, octavely related, or otherwise tonally related keys in the same manual, is of course of no consequence so far as this invention is concerned, since the same principle applies.

While I have shown and described a limited application of my invention for purpose of illustration, it will be apparent to those skilled in the art that numerous modiications and variations may be made in the form and Construction thereof, without departing from the more fundamental principles of the invention. l, therefore, desire by the following claim to include within the scope of my invention all such similar and modified forms of the apparatus disclosed by which substantially the results of the invention may be obtained by substantially the same or equivalent means.

l I claim:

vIn an electrical musical instrument of the organ ty c, a group of tone frequency oscillators each having voltage input terminals and adapted to oscillate at a certain amplitude individually when a certain potential is applied to individual terminals and to oscillate at a higher amplitude when a higher potential is applied to said individual terminals, a source of potential, a first group of connections, each including a voltage dropping load resistor and a switch, connecting said source individually to said terminals, a separate second group oi connections, cach including a second voltage dropping load resistor and a second switch, connecting said source individually to the same terminals in parallel with said iirst group of connections, a first group of playing keys individually adapted, when actuated, to close individual switches of said first group of connections, a second group of playing keys individually adapted, when actuated, to close individual switches of said second group of connections, and an output system connected to be supplied with input signals from said oscillators, the potential of said source being suicient, upon the closing of any one of said switclie to raise the potential of the connected terminal to said certain potential to produce oscillation at said certain amplitude, and, upon the closing of two switches connected to the same terminal, to raise the potential of said same terminal to said higher potential to produce oscillation at said higher amplitude.

References Cited by the Examiner UNITED STATES PATENTS 2,585,357 2/l952 Wayne 84-1.l7 2,681,585 6/1954 Hanert till-L24 2,687,665 S/l954 Hnnert 84-l.0l 2,790,906 4/1957 Hammond 84-l-ll 2,800,047 7/1957 Hanert 84--101 2,879,338 3/1959 George Sit-1.01 2,905,905 9/1960 George S4-l.0l 2,953,053 9/1960 Peterson 84-l.l7 3,038,365 6/1962 Peterson Slt-1.26 3,051,032 8/1962 Hanert 84-124 X JOHN W. HUCKERT, Primary Examiner.

CARL W. ROBINSON, ARTHUR GAUSS, Examiners. 

